The present invention relates to a method for fabricating a semiconductor device, and more particularly to a method for selectively epitaxially growing semiconductors.
A previously known method for fabricating a semiconductor device comprises the steps of epitaxially growing a semiconductor layer on a semiconductor substrate, in an apparatus for epitaxial growth, taking out the semiconductor substrate from the epitaxial growth apparatus, executing some steps required for fabricating devices such as lithography and etching, and epitaxially re-growing another semiconductor layer. Such a method is indispensable for fabricating a semiconductor device because it can increase the freedom in fabricating the semiconductor device. On the surface of the semiconductor layer to be seed crystal when the semiconductor layer is epitaxially regrown, however, impurities such as oxygen and carbon deposit during the steps of the photolithography and etching, or defects such as dislocations occur. Thus, the crystalline quality of the interfaces between semiconductor layers after the regrowth of the semiconductor will generally deteriorate.
In order to solve such a problem, disclosed is in JP-A-62-49659 a method for fabricating a semiconductor device comprising the steps of forming a surface protection layer of indium arsenide (InAs) on the surface of a GaAs layer epitaxially grown on the semiconductor substrate, taking out the semiconductor substrate from the epitaxial growth apparatus, executing the steps of the photolithography and the ion-implantation of O.sub.2, removing the surface protection layer, and epitaxially regrowing the GaAs layer.